<html>
<meta charset="utf8"/>
<head>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        body {
            width: 200px;
            height: 100px;
        }

        div {
            line-height: 100px;
            font-size: 42px;
            text-align: center;
        }
    </style>
</head>
<body>
<div id="clock_div"></div>
<script src="js/my_clock.js"></script>
</body>
</html>